Data centers are increasingly deploying a growing range of “bump-in-the-wire” services that perform packet processing on behalf of applications. Deep Packet Inspection (DPI) in particular is experiencing growing popularity for services such as, intrusion detection, content insertion, performance monitoring, traffic classification, and flow management. Conventional packet processing services often have strict performance requirements and should be transparent to the operating system (OS) or hypervisor and application software at traffic end-points. Those conventional packet processing services are typically implemented as custom hardware appliances, which become aggregation points in the data center that require careful data center-wide configuration to ensure that all appropriate network or storage traffic is routed correctly to the hardware appliances without first passing through untrusted or otherwise inappropriate devices. As aggregation points, the hardware appliances often require special-purpose acceleration hardware to handle relatively large data and packet rates. The resulting hardware appliances are typically expensive, difficult to scale incrementally, and have inflexible or hardwired functionality.